1. Field of the Invention
The present invention relates to an apparatus for detecting a foreign substance on an interleaving paper to be inserted between glass substrates, and more particularly, to an apparatus for detecting a foreign substance on an interleaving paper to be inserted between glass substrates, in which the process of detecting the foreign substance is automated to improve the detection efficiency.
2. Description of Related Art
In general, a surface of glass substrates that are used for flat panel displays, such as plasma display panels (PDPs) or liquid crystal displays (LCDs), are vulnerable to being scratched or contaminated when the glass substrates are stored or carried. In particular, in the case of glass substrates, such as a non-alkali glass substrate used for an LCD, in which an electrical circuit or the like is embedded in the surface of glass substrates, even a small scratch or insignificant contaminant on the surface can cause a disconnection of wire or a patterning defect.
In many cases, scratches occur on the surface of a glass substrate due to its misalignment with an adjacent glass substrate when glass substrates are stored such that they are stacked on each other or carried. In addition, glass substrates are frequently contaminated when a foreign substance, such as organic matter, become attached to the surface of the glass substrates. This is problematic because such organic matter is not easily removed from the surface of the glass substrates by cleaning with water.
In order to overcome this problem, an interleaving paper is interposed between adjacent glass substrates in order to separate the adjacent glass substrates from each other. However, in this case, scales originating from the paper, e.g., scales of a paper additive (kaolinite) such as aluminum silicate, are transferred to the surface of the glass substrates, thereby contaminating the glass substrates. Accordingly, in the related art, the quality of glass substrates is managed by individually detecting a foreign substance attached to the paper, using the human eyes. However, since the requirement of the interleaving paper between adjacent substrates is gradually increasing, it is becoming more difficult to inspect a large number of interleaving papers using the human eyes. It is also difficult to guarantee the reliability of the quality of the paper that is interposed between adjacent substrates, because the ability to detect a foreign substance varies depending on each individual inspector.
The information disclosed in this Background of the Invention section is only for the enhancement of understanding of the background of the invention, and should not be taken as an acknowledgment or any form of suggestion that this information forms a prior art that would already be known to a person skilled in the art.